Control system for multiunit engine operation



March 23, 1965 R. M. VOITIK 3,174,287

CONTROL SYSTEM FOR MULTIUNIT ENGINE OPERATION Filed Nov.. 25, 1964 v amwm @ipzmk @rz. Wm

United States Patent O Wis.

Filed Nov. 25, 1964, Ser. No. 413,802 9 Claims. ((31. 69-97) This invention relates to a control system for compounded engines having a master-slave relationship.

l-leretofore various fuel control means have been employed to control a plurality of engines connected to a common load. However, such controls have not proven entirely satisfactory as to performance and adaptability. In one such control the fuel supplied to the slave engine is varied in response to the speed of the master engine. In such a control, if increased fuel is supplied to the master engine the fuel will not be increased to the slave engine until the master engines speed is increased. If the load is increased at the same time fuel delivery is increased, the master engine may not actually speed up and thus fuel would not be increased to the slave engine. This would result in the master engine carrying a disproportionate share of the common load.

Some mechanical type fuel control systems have been employed for multiple engine installations. However, these have a number of operational disadvantages. In some instances the position of the engines relative to one another results in a complicated linkage which is not only exposed to accidental damage, but is also subject to wear at the pivot connections between its links and levers. Wear at the pivot connections results in ineffective control of the engines, particularly as to maintaining the desired ratio of engine power output.

it is a primary object of the present invention to provide a control system for multiunit engine operation wherein the slave engine fuel supply is adjusted in response to load changes and in response to selected speed change of the master engine.

It is a further object of this invention to provide a multiunit fuel control system which causes the slave engine to carry its desired share of the common load under various load and speed changes.

It is a further object of this invention to provide a fuel control for the slave engine which is responsive to difierences in the return fuel flow of injection pumps of the master and slave engines.

These and other objects and advantages of this invention will be apparent to those familiar with the art when the following description is read in conjunction with the drawing.

CONSTRUCTION Referring to the drawing, a master diesel engine 11 and two slave diesel engines 12, 13 are compounded, that is, connected to a common load, not shown, through an output shaft 14, which is an extension of crankshaft 17 of engine 12. The crankshafts 16, 17, 18 of the engines are interconnected by pulleys 21, 22, 23 and 24 and belts 26, 27. As illustrated the engines are of the same size and operate at the same speed. Thus the identical gear type fuel supply pumps 28, 29, 31 driven by the engines 11, 12, 13, respectively, operate at the same speed. The engine driven supply pumps 28, 29, 31 draw fuel from reservoirs 32, 33, 34 and deliver it to fuel injection pumps 36, 37, 38 by Way of supply pump delivery passages 39, 41, 42. Fuel injectors, not shown, are supplied fuel by way of injector lines 43, 44, 45 connected to injection pumps 36, 37, 38, respectively.

The fuel injection pumps 36, 37, 38 have fuel delivery control elements 47, 48, 49 reciprocable between low and 3,174,281 Patented Mar. 23, 1965 high fuel delivery settings. The illustrated fuel injection pumps are multiple plunger pumps and the fuel control elements 47, 48, 49 have gear racks which cooperate with means for controlling the quantity of fuel delivered by the pump to their associated injection lines. The fuel supplied by the supply pumps 28, 29, 31 and not delivered by the injection pumps 36, 37, 38 to the injection lines of engines 11, 12, 13 is exhausted by way of return passages in the form of conduits 51, 52, 53.

Fuel delivery control element 47 of pump 36 is controlled by a speed governor 56 driven by engine 11 and thus is sensitive to its speed. Means in the form of a throttle lever 57 is provided to adjust the sensitivity of control element 47 to the governor 56. The throttle lever, which is pivoted about an axis 58 on the governor housing 59, is connected to suitable linkage, not shown, for selective control by manually operable means, for instance.

The fuel delivery to slave engine 12 is regulated by an actuator 61, having a piston component 62 connected to control rod 48 and a cylinder component 63 secured to engine 12 by a bracket 64. The pressure chamber 67 at one end of the actuator 61 is connected to return passage 51 and the pressure chamber 69 at the other end of the actuator is connected to return passage 52. A return to reservoir passage 66 is connected to chamber 67 and a return to reservoir passage 68 is connected to chamber 69. Return flow from fuel injection pump 36 thus passes to reservoir 71 by way of passage 66 and fuel return flow from injection pump 37 passes to reservoir 71 by way of passage 68. Passages 66 and 68 are at all times connected in fluid communication with return passages 51, 52, respectively. The return to reservoir passages 66, 68 have flow restrictors 72, 73 in them to create back pressure for accurate control of actuator 61. Restrictor 73 is adjustable, by screw 74, to permit initial adjustment of the slave engine fuel control system to properly balance the loads carried by the engines 36, 37.

A similar fuel control system is provided for slave engine 13. A hydraulic actuator 81 has a cylinder component 89 secured to engine 13 through bracket and a piston component 91 secured to fuel control element 49. Pressure chambers 83, 84 at opposite ends of actuator 81 are connected to conduits 32, 53, respectively. Thus chamber 83 is in constant fluid communication with return passage 51 of engine 11, since conduit 82 is connected to chamber 67 of actuator 61. The restriction 72 in return to reservoir passage 66 is effective to maintain the desired back pressure in chambers 6'7, 83 for proper operation of the fuel control system. A return to reservoir passage 86 is connected in fluid communication with chamber 84 and thus with return passage 53. The fluid exhausted from fuel injection pump 38 passes to the reservoir 87 by way of an adjustable restn'ctor 88 in passage 86. By adjustment of screw 89 of restrictor 88, the fuel delivery of injector 38 can be adjusted so that engine 13 carries its proper portion of the total load.

OPERATION Changes in throttle setting First let us assume that the operator adjusts the throttle lever 57 clockwise to an increased fuel setting. This decreases the sensitivity of the control element 47 to the governor 56, thus allowing the control element 47 to move to the right to an increased fuel setting. It should be understood that the fuel delivery control elements 47, 48, 49 are biased to the right by spring means, not shown. Such outward adjustment of control element 47, causes an increased portion of the fuel delivered by the supply pump 28 to be delivered to the injector lines 43, thereby decreasing the return flow through return passage 51. This results in decreasing the pressure in chamber 67 of actuator 61 associated with the slave en gine 12. Such a decrease in pressure in chamber 67 causes the piston component 62 to move to the right to increase the fuel delivery of injection pump37 to the injection lines 44. When the fuel delivery to the injection lines 44 by fuel injection pump 37 has increased sufficiently to decrease the exhaust flow through return passage 52 to cause a reduced pressure in chamber 69 matching the reduced pressure in chamber 67, the piston 62 will stop movement and engine 12 will be delivering its proper portion of the total power for driving the load. Since passage 82 is 'connected'to return flow passage 51, the pressure in chamber '83 of the actuator 81 for slave engine 13 Will also drop in response to decreased flow in the return passage 51 of engine 11. In a similar manner the fuel control element 49 and piston 91 of actuator 81 will move to the right to an increased fuel setting causing injection pump 38 to use'a greater portion of the delivery of supply pump 31. The return flow through passage 53 decreases thereby decreasing the pressure in chamber 84 to match the pressure in chamber 83.

When the throttle control lever is moved counterclock-v wise to decrease the fuel delivery of injection pump 36 the increase in the return flow through return passage 51 results in the fuel control elements 47, 48, 49 being moved to the left practically simultaneously to increase fuel delivery of the injection pumps 36, 37, 38. This results in decreased flow in return passages 52, 53, thus decreasing the pressure in the actuatorfchambers 69, 84 to match the pressures in actuator chambers 67, 83.

Changes in load When the load driven by shaft 14 is decreased the engines 11, 12, 13 will tend to speed up and the governor 56 will adjust the fuel control element 47 to the left to a decreased fuel setting thereby reducing the speed of master engine 11 to substantially its predetermined speed established by the setting of throttle lever 57. V This will result in less fuel delivery by pumping 36 to the injection lines 43 and increased fuel flow through return passage 51'. The increase in fuel flow in passage 51 causes an increased pressure in chambers 67 and 83 of actuators 61 and 81, thus causing the fuel delivery control, elements 48, 49 to be moved to the left to decreased fuel settings.- Such movement in turn resultsjin increased return flow through passages 52, 53 creating increased pressure in chambers 69 and 84 to match the pressure in chambers 67 and 83, at which point the fuel delivered to each of the slave engines 12, 13 is the same quantity as that delivered to master engine 11. ,Although I show five fuel reservoirs 32, 33, 34, 71, 87 these are preferably a single fuel reservoir, where spacing and installation circumstances permit.

From the foregoing it is apparentthat my fuel control system almost instantaneously adjusts the slave engines in response to changes in fuel setting effected by movement of throttle lever 57 and load changes sensed by the master engine governor. accurate load balance between the engines. That is, each engine carries its share of the load within a very close tolerance throughout the operating range. The torque curve and other governor characteristics of the master engine are closely imitiated by the slave units. Since flexible hydraulic lines are used in the control system, the system is extremely fiexibleinsofar as the variety of installations in which the system can be utilized. Only the master engine requires a governor and the slave engines.

utilize double acting hydraulic actuators in place 'of governors, thus my system is very low in cost. The master engine can be operated to drive the load by itself or can,

This system provides a more 4 elusive property or privilege is claimed are defined as follows:

1. A load sensitive fuel control system for compounded master and slave engines, comprising:

a master engine driven fuel supply pump having a fuel delivery varying with the speed of said master engine,

first delivery means for delivery a portion of said fuel delivery of said master engine supply pump to said master engine including a fuel delivery control element shiftable to vary fuel delivery to said master engine,

a governor sensitive to master engine speed connected in controlling relation to said control element and means for varying the responsiveness of said control element to said governor,

a slave engine driven fuel supply pump having a fuel delivery varying with the speed of said slave engine, and

second delivery means for delivering a portion of said fuel delivery of said slave engine supply pump to said slave engine including,

a fuel delivery control member shiftable to vary fuel delivery to said slave engine,

a double acting hydraulic actuator having piston and cylinder components one of which is secured against axial movement relative to said slave engine and the other of which is connected in controlling relation to said control member,

a first fuel return passage interconnecting said first delivery means and one end of said actuator,

a second fuel return passage interconnecting said second delivery means and the other end of said actuator,

a pair of return to reservoir passages connected in fluid communication to said fuel return passages, respectively, and

restriction means in each of said return to reservoir passages, respectively, at least one of which is adjustable.

2. The structure set forth 'in'claim 1 wherein said adjustable restriction means is in said second fuel. return passage.

3. The structure set forth in claim 1 wherein each of said fuel delivery means includes a fuel injection pump, said'fuel delivery con'trol element and member constituting parts, respectively, of said fuel injection pumps.

4. Thestructure set fo'rth'in claim 3 wherein said adjustable restriction means is in said second fuel return passage.

5. A load sensitive fuel control system for com pounded master andslave engines each of which has an engine driven fuel supply pump whose fuel delivery varies with speed and delivery means for delivering part of such fuel delivery to the engine and exhausting the remainder through a return passage including a fuel delivery control element movable between high speed and low speed setting, said system comprising:

a speed responsive governor operatively connected to said master engine and in controlling relation to'the latters fuel control element,

'a double actinghydraulic actuator having piston and cylinder components,

means securing one of said components against axial movement relative to said slave engine,

means connecting the other of said components in controlling relation to said control element of said slave engine,

means connecting said return passages to opposite ends of said actuator, respectively,

a pair of reservoir passages connected in fluid communication with said return passages, respectively, and

restriction means in each of said reservoir passages,

respectively, at least one of which is adjustable. 6. The structure set forth in claim 5 wherein said each of said delivery means includes a fuel injection pump of which said fuel delivery control element is a part and wherein said actuator moves said control element for said slave engine toward its high speed setting upon the flow of fuel in said return passage for said master engine decreasing.

7. The structure set forth in claim 6 wherein said adjustable restriction means is in the reservoir passage connected in fluid communication with the return passage for said slave engine.

8. A load sensitive fuel control system for compounded master and slave engines comprising:

supply pump means delivering fuel to said engines at a predetermined ratio,

delivery means for each engine delivering part of such fuel delivery to the associated engine and exhausting the remainder through a return passage, each said delivery means including a fuel delivery control element movable between high speed and low speed setting,

a speed responsive governor operatively connected to said master engine and in controlling relation to the latters fuel control element,

a double acting hydraulic actuator having piston and 5 cylinder components,

means securing one of said components against axial movement relative to said slave engine,

means connecting the other of said components in controlling relation to said control element of said slave 10 engine,

means connecting said return passages to opposite ends of said actuator, respectively, a pair of reservoir passages connected in fluid communication with said return passages, respectively, 15 and restriction means in each of said reservoir passages,

respectively, at least one of which is adjustable. 9. The structure set forth in claim 8 wherein each of said delivery means includes a fuel injection pump of 20 which said fuel delivery control element is a part.

No references cited.

JULIUS E. WEST, Primary Examiner. 

5. A LOAD SENSITIVE FUEL CONTROL SYSTEM FOR COMPOUNDED MASTER AND SLAVE ENGINES EACH OF WHICH HAS AN ENGINE DRIVEN FUEL SUPPLY PUMP WHOSE FUEL DELIVERY VARIES WITH SPEED AND DELIVERY MEANS FOR DELIVERY PART OF SUCH FUEL DELIVERY TO THE ENGINE AND EXHAUSTING THE REMAINDER THROUGH A RETURN PASSAGE INCLUDING A FUEL DELIVERY CONTROL ELEMENT MOVABLE BETWEEN HIGH SPEED AND LOW SPEED SETTING, SAID SYSTEM COMPRISING: A SPEED RESPONSIVE GOVERNOR OPERATIVELY CONNECTED TO SAID MASTER ENGINE AND IN CONTROLLING RELATION TO THE LATTER!S FUEL CONTROL ELEMENT, A DOUBLE ACTING HYDRAULIC ACTUATOR HAVING PISTON AND CYLINDER COMPONENTS, MEANS SECURING ONE OF SAID COMPONENTS AGAINST AXIAL MOVEMENT RELATIVE TO SLAVE ENGINE, MEANS CONNECTING THE OTHER OF SAID COMPONENTS IN CONTROLLING RELATION TO SAID CONTROL ELEMENT OF SAID SLAVE ENGINE, MEANS CONNECTING SAID RETURN PASSAGES TO OPPOSITE ENDS OF SAID ACTUATOR, RESPECTIVELY, A PAIR OF RESERVOIR PASSAGES CONNECTED IN FLUID COMMUNICATION WITH SAID RETURN PASSAGES, RESPECTIVELY, AND RESTRICTION MEANS IN EACH OF SAID RESERVOIR PASSAGES, RESPECTIVELY, AT LEAST ONE OF WHICH IS ADJUSTABLE. 